For the past century, since heading the first Australian-led Antarctic expedition, Sir Douglas Mawson has been considered a national hero. Now historian David Day claims he was largely to blame for the deaths of his two companions.

During the 1911-14 expedition Mawson's team mapped more than 1000km of the Antarctic coastline closest to Australia. But tragedy struck as he returned to base with team members Xavier Mertz, a Swiss scientist and former ski champion, and Belgrave Ninnis, a young British soldier.

Ninnis fell to his death down a crevasse in December 1912, taking with him a team of dogs, a tent and a sled with most of the men's food. Barely three weeks later, Mertz died, leaving Mawson - 160km from base - to return alone, accomplishing what has been called "the greatest story of lone survival in polar exploration".

Until now, his reputation has remained intact. But writing in the Australian, Day - author of Antarctica: A Biography - argues that Mawson's "ambition and inexperience" played a large role in Ninnis's and Mertz's deaths.

Day criticises Mawson, a Yorkshire-born geologist and engineer who was just 30 when he led the expedition, for a series of errors, including siting the main base - home to 22 men - in a place buffeted by near-constant gales and setting up only one supply cache.

Returning to base, Mawson made the "ill-fated decision" to put most of the food on one sledge. As he and Mertz struggled on, they shot and ate some of the remaining dogs, possibly giving themselves vitamin A poisoning from the animals' livers.